A German physics blog has installed a pretty fascinating gadget and you may enjoy it here, too. If you're irritated by the bubbles or if they slow you down, you - a client - can turn them off if you click "Options" in the upper right corner and if you continue with a comprehensible dialog box.
Before you click to get to any external website, you will see a preview how the target looks like. It doesn't work with the Haloscan comments and some links that are generated in certain dynamical ways, but it does work for the regular links as well as "links to this post" as well as the blogroll as well as the translations to other languages (flags). Wait for half a second and you will usually obtain a high-quality preview.